I didn't visit the much talked about Momofuku Milk Bar the last time I was in New York City. I did eat at Momofuku Noodle Bar where I indulged in a bowl of their famous ramen and those amazing pork belly buns, but never made it to Milk Bar. Milk Bar is best known for their crack pie and their compost cookies. The compost cookie recipe has been floating around the internet ever since Christina Tosi, Milk Bar's pastry chef, appeared on Live with Regis and Kelly.
In the past the cookie probably would've been called a kitchen sink cookie (as in a cookie with everything but the kitchen sink thrown into it), but in this very environmentally conscious day and age, compost cookie sounds much more trendy. I think what really makes it a compost cookie is the addition of used coffee grounds. Yup, used grounds. I've read that others who have tried the compost cookie recipe thought the coffee grounds didn't really add much to the cookie, but I whole-heartedly disagree. Even though my grounds were used (and therefore much of the "coffee-ness" was already extracted) I could still taste the coffee in my cookie. Maybe it depends on the freshness and type of coffee beans used and how long the used grounds have been sitting after extraction? My used grounds were from locally roasted Blue Bottle beans ground right before making my pour over coffee and the used grounds had only been sitting around for a couple hours. I loved the flecks of coffee throughout the cookie. Of course you don't have to use used coffee grounds. Adding some unused ground coffee would work too (but it would be less compost-y).
The recipe calls for refrigerating the cookie dough for at least one hour before baking to prevent the cookies from spreading too much. I was crunched for time so I skipped the chilling and just spread the just made dough into a baking pan to make cookie bars. After spreading the dough in the pan I gave it a nice sprinkling of Maldon sea salt to play up the salty sweet nature of my cookie bar.
You can use any combination of add-ins and snack foods like chocolate chunks, butterscotch, nuts, dried fruits, candies (like chopped up peanut butter cups, Snickers, Rollos), breakfast cereal, salted pretzels, salted potato chips, oatmeal. I went with 60% cacao chocolate chips, Rice Krispies cereal, crushed salted pretzels and sliced almonds. Use whatever you like - sky's the limit!
Compost Cookie Bar
(adapted from the Momofuku compost cookie recipe on the Regis and Kelly website)
1 3/4 cups all purpose flour
2 tsp baking powder
1 tsp baking soda
2 tsp kosher salt
1 cup (8 ounces/2 sticks) unsalted butter
1 cup granulated sugar
3/4 cup light brown sugar
1 Tbsp corn syrup (you can substitute 1 Tbsp honey or maple syrup)
1 tsp pure vanilla extract
2 large eggs
2 Tbsp used coffee grounds
1 1/2 cups any baking add-ins (chopped chocolate, chocolate covered raisins, rollos, rice krispies cereal, etc.)
1 1/2 cups your favorite snack foods (potato chips, pretzels, nuts, etc.)
Preheat oven to 350F. Line a 9 x 13 x 2 - inch baking pan with parchment paper.
In a medium bowl, sift together the flour, baking powder, baking soda, and salt. Set aside.
In a stand mixer with the paddle attachment, cream butter, sugars and corn syrup on medium high for 2-3 minutes until fluffy and pale yellow in color. Scrape down the sides of the mixing bowl with a spatula.
On a lower speed, add eggs and vanilla to incorporate. Increase mixing speed to medium-high and start a timer for 10 minutes. During this time the sugar granules will fully dissolve, the mixture will become an almost pale white color and your creamed mixture will double in size.
When time is up, on a lower speed, add the flour mixture. Mix 45-60 sec just until your dough comes together and all remnants of dry ingredients have incorporated. Do not walk away from your mixer during this time or you will risk over mixing the dough. Scrape down the sides of the mixing bowl with a spatula.
On low speed, add in the coffee grounds and your chosen baking add-ins. Mix for 30-45 sec until they evenly mix into the dough. Add in your favorite snack foods last, paddling again on low speed until they are just incorporated.
Spread batter in your prepared 9 x 13 x 2 - inch pan. Sprinkle the top of the batter with about 1/2 tsp fine sea salt (optional). Bake at 350F for 30-35 minutes. Let cool in pan on a wire rack. Cut into bars when cooled to room temperature.